The swiftly burgeoning study of the earlier twenty years on agonist-antagonist analgesics and opioid receptors makes this exhaustive evaluate of opioid anal­ gesics relatively correct and well timed. After an introductory bankruptcy the extra 12 chapters commence logically with morphine and congeners (4- epoxymorphinans) and finish with opioid receptors.

This observation is most easily rationalized in terms of the hydroxyl groups undergoing deprotonation when exposed to FÀ (an anion recognized for its basicity in organic milieus) a chemical change that was expected to give rise to an intramolecular charge-transfer interaction. Deprotonation also likely accounts for the efficacy of a set of polyhydroxybenzoxazole-based colorimetric and fluorometric chemosensors for fluoride (cf. structure 71) introduced by the Lee group, whose other contributions are featured elsewhere in this chapter [81].